JP2006505092A - Organic light emitting device structure having sealing structure that functions as multilayer mirror - Google Patents

Abstract

It provides a novel structure for OLED devices that can simultaneously achieve desirable optical and barrier properties with a single multilayer stack. The OLED structure is formed on (a) a substrate (110), (b) a substrate, (1) a first electrode (142), and (2) a light emitting unit (1) formed on the first electrode ( 144) and (3) an organic light-emitting device (140) having a second electrode (146) formed on the light-emitting portion and emitting light of a predetermined range of wavelengths when turned on, and (c) (1) a planarization layer (121a to 121c) having a first refractive index, and (2) a high-density layer (122a to 122a) having a second refractive index different from the first refractive index. 122c) and a multilayer mirror (120) arranged alternately and continuously. The thicknesses of the planarization layer and the high-density layer are selected so that the multilayer mirror transmits light having a peak wavelength within a predetermined range of wavelengths. The planarization layer and the dense layer cooperate to prevent water and oxygen permeation.

Description

  The present invention relates to structures for protecting organic light emitting devices from harmful species in the surrounding environment and structures for reflecting and transmitting light emitted from such devices.

  Organic light emitting devices (hereinafter referred to as OLED) including polymer organic light emitting devices and small molecule organic light emitting devices are, for example, laptop computers, television receivers, digital watches, telephones, pagers, mobile telephones, computers. Are used in various types of virtual-view type displays and virtual-and direct-view type displays. Unlike inorganic semiconductor light-emitting devices, organic light-emitting devices generally have a simple structure, are relatively easy to manufacture, and are inexpensive. Furthermore, the OLED can be easily used for applications that require a wide variety of colors and for devices with a wide display area.

  Two-dimensional OLED arrays for imaging applications are known in the art and typically include an OLED display area consisting of a plurality of active pixels arranged in rows and columns. FIG. 1A is a diagram (cross-sectional view) schematically showing a conventional OLED structure. The OLED structure shown here includes a single active pixel 15, and the active pixel 15 is formed on an anode 12 (hereinafter simply referred to as an anode) 12 that is, for example, an electrode region, and on the anode 12. The light emitting layer 14 and a cathode portion (hereinafter simply referred to as a cathode) 16 which is the other electrode portion formed on the light emitting layer 14 are configured. The active pixel 15 is disposed on the substrate 10. The cover 20 and the substrate 10 cooperate with the sealing portion 25 to prevent oxygen and water vapor from entering the active pixels 15 from the external environment.

  In the conventional method, the light from the light emitting layer 14 is transmitted downward through the substrate 10. In such a “bottom emitting” configuration, the substrate 10 and the anode 12 are formed from a transparent material. On the other hand, in this configuration, the cathode 16 and the cover 20 do not need to be transparent.

  Other OLED structures are also known, such as “top-emitting” OLEDs and transparent OLEDs (TOLEDs). In the top extraction OLED, the light emitted from the light emitting layer 14 is transmitted upward through the cover 20. Therefore, in this case, the substrate 10 may be formed from an opaque material, and the cover 20 needs to be formed from a transparent material. In the top extraction configuration based on the design as shown in FIG. 1A, a transparent material is used for the cathode 16, but the anode 12 need not be transparent. In the other top extraction configuration shown in FIG. 1B, the positions of the anode 12 and cathode 16 in FIG. 1A are interchanged, and thus a transparent anode 12 is used. In this case, the cathode 16 may be opaque. Such a configuration is sometimes referred to as an “inverted configuration”.

  In a TOLED where light is emitted in both upward and downward directions (i.e., from both the top and bottom surfaces of the device), the substrate 10, anode 12, cathode 16, and cover 20 must all be transparent. This configuration may have a configuration similar to that shown in FIG. 1A or 1B.

  When forming OLEDs, a layer of reactive metal is typically used as the cathode to achieve efficient electron injection and low operating voltage. However, reactive metals and interfaces between reactive metals and organic materials are sensitive to oxygen and moisture, which severely limits the lifetime of the device. It is known that moisture and oxygen have other adverse effects. For example, it is known that moisture and oxygen increase the “dark spot area” in OLEDs. Various barrier parts are known in the art to prevent the entry of such species from the external environment. Specific examples thereof include US Pat. Nos. 5,757,126, 6,146,225, and 6,268,295, the entire disclosures of which are incorporated herein by reference. Multi-layer structures disclosed in US Pat.

  Furthermore, it is also known to use a distributed Bragg reflector (hereinafter referred to as DBR) in connection with the OLED. These DBRs often have a multilayer mirror structure using a so-called “quarter-wave stack”. With such a structure, in particular, the spectrum of the emission band can be narrowed, the peak output luminance can be increased, and the direction of outgoing light can be changed. Examples of such structures include, for example, Dodabalapur et al., US Pat. No. 5,674,636, Doda Balapu et al., US Pat. No. 5,814,416, Bulovic et al. U.S. Pat. No. 5,834,893, Jones et al. U.S. Pat. No. 5,920,080, and the like. Each of these documents is hereby incorporated by reference.

  It is an object of the present invention to provide a new structure used in connection with OLED devices that simultaneously functions as a multilayer mirror and as a barrier against harmful chemical species from the external environment.

  An organic light emitting device structure according to the present invention is formed on (a) a substrate, (b) a substrate, a first electrode, a light emitting portion formed on the first electrode, and a light emitting portion. An organic light-emitting device that emits light having a predetermined wavelength when turned on, and (c) a planarization formed on a substrate and having (1) a first refractive index And (2) a multilayer mirror in which high-density layers having a second refractive index different from the first refractive index are alternately and continuously disposed. The thicknesses of the planarization layer and the high-density layer are selected so that the multilayer mirror transmits light having a peak wavelength within a predetermined range of wavelengths. The planarization layer and the dense layer cooperate to prevent water and oxygen permeation.

  The multilayer mirror is preferably a quarter-wave stack. Preferably, the first electrode is an anode and the second electrode is a cathode, but may be configured in the opposite manner. Furthermore, depending on the application, the organic light emitting device may be any one of an upper extraction device, a lower extraction device, and a transparent device.

  In some embodiments, the quarter wave stack is disposed between the organic light emitting device and the substrate, and the first electrode is a transparent electrode. In these embodiments, the second electrode may also be transparent, in which case an additional quarter-wave stack may be formed on the second electrode if desired. On the other hand, the second electrode may be opaque. In this case, the second electrode is preferably a reflective electrode having reflectivity.

  In other embodiments, the quarter wave stack is disposed on the organic light emitting device and the second electrode is a transparent electrode. In this embodiment, the first electrode may be opaque. In this case, the first electrode is preferably a reflective electrode having reflectivity.

  An organic light emitting device structure according to another aspect of the present invention includes (a) a transparent substrate, (b) a transparent anode formed on the transparent substrate, a light emitting portion formed on the transparent anode, and a light emitting portion. An organic light emitting device that is turned on and emits light of a wavelength in a predetermined range; and (c) a planarization formed on a substrate and having (1) a first refractive index. And a quarter-wave stack in which (2) a high-density layer having a second refractive index different from the first refractive index is alternately and continuously disposed.

  The thicknesses of the planarization layer and the high density layer in this embodiment are selected so that the quarter wavelength stack transmits light having a peak wavelength within a predetermined range of wavelengths. Furthermore, the planarization layer and the dense layer cooperate to prevent water and oxygen permeation.

  An organic light emitting device structure according to another aspect of the present invention is formed on (a) a substrate, (b) a reflective anode, a light emitting portion formed on the reflective anode, and a light emitting portion. An organic light emitting device that is turned on and emits light of a wavelength in a predetermined range; (c) a planarization layer formed on a substrate and having (1) a first refractive index; (2) a quarter-wave stack in which high-density layers having a second refractive index different from the first refractive index are alternately and continuously disposed. Again, as above, the thicknesses of the planarization layer and the high density layer are selected so that the quarter wavelength stack transmits light of a peak wavelength within a predetermined range of wavelengths, The dense layer cooperates to prevent water and oxygen permeation.

  In the present invention, the desired optical and barrier properties can be achieved simultaneously with a single multilayer stack.

  These and other embodiments and advantages of the invention will be apparent to those skilled in the art from the following description.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating preferred embodiments of the present invention. However, the present invention can be implemented in a format different from the embodiments described herein, and the configuration of the present invention is not limited to the format shown here.

  It should be noted that the drawings are only simplified schematic representations, as in general drawings, and the actual structure differs from the drawings in many respects, including the relative scale of the components. Yes.

  As used herein, a “layer” of a given material refers to the portion of the material whose thickness is small relative to its length and width. Layers include sheets, foils, films, laminations, coatings, and the like. In this specification, the layers are not necessarily planar, and may be curved, bent or bent into other shapes, for example, so as to at least partially enclose other components. A “layer” may include two or more sublayers, or “sublayers”.

  FIG. 2 shows the structure of an OLED device indicated generally by the reference numeral 100, which comprises a substrate 110, a multilayer mirror (in this case a quarter wavelength stack) 120, an OLED 140 and a cover part 150. With.

  The OLED 140 may be any known OLED. For example, as described above, the OLED 140 includes the electrode portions 142 and 146 that function as an anode and a cathode thereof. Further, the OLED 140 includes a light emitting unit 144 (radiating unit) 144 disposed between the electrode units 142 and 146.

  The light emitting unit 144 has (a) a three-layer structure (that is, a double hetero structure structure) composed of a hole transport layer, a light emitting layer, and an electron transport layer, and (b) a hole transport layer and a light emitting and electron transport function. A two-layer configuration consisting of a layer to be provided, or a two-layer configuration consisting of an electron transport layer and a layer having a light emission and hole transport function (ie, a single heterostructure configuration) (c) hole transport, electron transport, light emission It can be provided in connection with a number of well known configurations, including functional single layer configurations (ie, single layer configurations). In each configuration, additional layers may be added, for example, a layer for promoting hole injection or electron injection may be added, or a layer for blocking holes or electrons may be provided. Good. Various configurations of such devices are disclosed, for example, in US Pat. No. 5,707,745, the entire disclosure of which is incorporated herein by reference. More complex OLED structures have also been put into practical use in the art.

  In the embodiment shown in FIG. 2, in many cases, the combination of the electrode portion 146 and the quarter-wave stack 120 causes a microcavity effect. In this embodiment, the electrode unit 142 is often transparent to output light having a predetermined wavelength that is a desired output wavelength of the OLED. Here, “transparent” means that the amount of attenuation of output light passing through the region (in this case, the electrode part 142) is small, and the transmittance is usually larger than 80% at a predetermined wavelength. .

  As a preferred configuration, when the electrode portion 142 is selected as an anode, materials having appropriate transparency include metal oxides such as indium tin oxide (hereinafter referred to as ITO), zinc oxide-tin, and the like. Other materials well known in the art are used. When the electrode part 142 is selected as the cathode, examples of suitable transparent materials include metal / metal oxide combinations such as Mg-Ag / ITO and LiF / Al / ITO, or those well known in the art. Other materials are used.

  As a preferred embodiment of the structure shown in FIG. 2, when the OLED device 100 shown in FIG. 2 is a bottom-out OLED, the substrate 110 needs to be transparent, while the cover 150 does not need to be transparent. In this configuration, the electrode portion 146 is preferably formed of a reflective material, for example, in order to enhance the cavity effect of the OLED device 100. Here, “reflective” means that a substantial amount of output light of a given wavelength, typically at least 80%, is reflected. When the electrode portion 146 is selected as the cathode, suitable reflective materials include aluminum, aluminum / lithium, aluminum / lithium fluoride, aluminum / lithium oxide, and other materials well known in the art. it can. On the other hand, when the electrode portion 146 is selected as the anode, as the material having appropriate reflectivity, for example, gold, chromium, nickel, platinum, and other materials known in the art can be used.

  When the OLED device 100 shown in FIG. 2 is a TOLED, both the substrate 110 and the cover 150 are transparent. Furthermore, the electrode part 146 is also transparent. Examples of the transparent material that can be used for the electrode portion 146 include the same materials as those described above with respect to the electrode portion 142.

  When the OLED device 100 shown in FIG. 2 is an upper extraction type OLED, the cover 150 and the electrode portion 146 are transparent.

  A particularly preferred configuration of the OLED device 100 shown in FIG. 2 is a downward take-out configuration, where the substrate 110 is a transparent substrate, the electrode portion 142 is a transparent anode, and the electrode portion 146 is a reflective cathode.

  FIG. 3 shows the structure of an OLED device that is another embodiment of the present invention, indicated generally at 200. In this embodiment, a multilayer mirror (in this case, a quarter-wave stack 220) is provided on the electrode 246 on the side opposite to the substrate 210.

  As will be described in more detail later, the quarter-wave stack 220 according to the present invention has the function of preventing the invasion of harmful chemical species in the surrounding environment, and therefore, in this embodiment, it is not necessary to provide a separate cover. . In FIG. 3, the quarter wavelength stack 220 is directly provided on the electrode portion 246, but an intervening region including any substrate used in forming the quarter wavelength stack 220 may be provided. Good. In addition, the intervening layer can be provided between various other layers of the device according to the present invention as in the prior art.

  In the embodiment shown in FIG. 3, the microresonator effect is generated by the combination of the electrode portion 242 and the quarter wavelength stack 220. In this embodiment, the electrode portion 246 is transparent.

  When the OLED device 200 is a downward take-out type OLED, or when the OLED device 200 is a TOLED, the substrate 210 and the electrode part 242 are also made transparent.

  As a preferred embodiment of the structure shown in FIG. 3, when the OLED device 200 is an upper extraction type OLED, the electrode portion 242 can be formed from a reflective material to enhance the resonator effect of the OLED device 200, for example. Alternatively, the electrode portion 242 may be formed of a transparent material in the upper extraction configuration.

  As in FIG. 2, the electrode portion 242 is preferably an anode, and the electrode portion 246 is preferably a cathode.

  Many other configurations are possible. For example, the OLED device 300 shown in FIG. 4 includes a substrate 310, two multilayer mirrors (in this case, quarter-wave stacks 320a and 320b), and an OLED 340. The microresonator effect is generated by the combination of the quarter-wave stack 320a and the quarter-wave stack 320b. In this embodiment, the electrode portions 342 and 346 are both transparent. Here, the electrode portion 342 is preferably an anode and the electrode portion 346 is preferably a cathode.

  The OLED device 300 may be a lower extraction type, an upper extraction type, or a transparent type, and the same modification as described above can be applied to this embodiment. For example, when the OLED device 300 is a TOLED or a lower extraction device, the substrate 310 is transparent. A preferred configuration in the embodiment shown in FIG. 3 is a transparent (TOLED) configuration.

  As described above, the substrates 110, 210, 310 and cover 150 may or may not be required to be transparent depending on the desired configuration. Common materials for these components include polymers, ceramics, semiconductors and metals.

  The metal does not have substantial transparency at the thickness commonly used for substrates and covers, but provides excellent barrier properties. Furthermore, the metal can be provided in various configurations, such as metal cans or metal foils. Suitable metals for this purpose can include aluminum, gold, nickel, nickel alloys, indium and other materials well known in the art.

  Semiconductors (eg, silicon), like metals, usually do not show good transparency. However, the semiconductor provides a substrate that has good barrier properties against water, oxygen, and other harmful chemical species, and that can create an electrical circuit.

  Ceramics often exhibits low transparency and transparency. The preferred ceramic is glass, more preferably soda lime glass and borosilicate glass.

  When optical transparency is desired, it is often desirable to use a polymer as the material. However, when a polymer is selected as the substrate or cover, it is desirable to provide an additional barrier region since most polymers are transmissive. If necessary, this function may be realized by a multilayer mirror according to the present invention.

  In the particular embodiment shown in FIG. 2, the material of the substrate 110 is often optical properties, flexibility, conformability to other surfaces, and dimensions during processing (eg, assuming a wafer-based process). Selected on the basis of one or more advantageous properties, including, for example, sufficient stability with other components (eg, in this embodiment, a coherent barrier layer of the quarter wave stack 120), etc. The

  If flexibility is desired, the substrate 110 may be composed of paper, fabric, metal anchors, flexible glass (available from Schott Glass Technologies) and / or polymer layers. More preferred flexible substrate materials include one or more polymer components such as polyesters, polycarbonates, polyethers, polyimides, polyolefins, fluoropolymers, etc. that have strong adhesion to other materials. Such polymer components are available, for example, as homopolymers, copolymers, polymer blends, and the like. Specific examples of preferred polymer components include, for example, polyethersulfone, polyarylate, polyester carbonate, polyethylene naphthalate, polyethylene terephthalate, polyetherimide, polyacrylate, Kapton available from DuPont. : A polyimide such as a polyimide thin film, a fluoropolymer such as Aclar ™ fluoropolymer available from Honeywell, an Appear available from BF Goodrich, Inc. ) Polynorbornene (PNB), Arton (trademark) available from BF Goodrich. When these materials are used, the thickness of the substrate 110 is typically in the range of 75 to 625 μm.

  A multilayer mirror (in this example, a quarter wave stack 120) includes a series of planarizing materials 121a-121c and high-density materials 122a-122c on a substrate 110. Can be formed by forming a cooperative barrier layer. These cooperating barrier layers are alternately stacked. Preferably, 2-10 pairs (or more) of layers are used. In other words, FIG. 2 shows three pairs of layers, but other layer configurations are possible. Furthermore, as shown in FIG. 2, the bottom layer is desirably a planarizing material layer 121a, but the bottom layer may be, for example, a high-density material layer. Similarly, although the top layer shown in FIG. 2 is the high-density material layer 122c, this top layer may be a planarizing material layer.

  As a result, the multilayer mirror structure according to the present invention also functions as a composite barrier layer that is suitable for preventing intrusion of moisture and oxygen. Furthermore, these structures are inherently flexible and are therefore very suitable for the production of flexible OLEDs (FOLEDs).

  Note that “planarizing material” means a material that does not form a surface reflecting irregular irregularities of the underlying surface, but forms a smooth planar surface with the material. . A preferred material for the planarizing material is a material that, when deposited on the surface, becomes a non-conformal liquid. An example of such a material is an acrylate monomer (the acrylate monomer is usually exposed to ultraviolet light or an electron beam to crosslink the monomer to form a polyacrylate). Preferred planarizing materials include, for example, fluorinated polymers, parylene, cyclotenes, polyacrylates. The planarizing material layers 121a to 121c can be formed by techniques well known in the art such as dipping, spin coating, sputtering, vapor deposition coating, spraying, flash vapor deposition, chemical vapor deposition, and the like.

A high density material means a material with a sufficiently small interatomic distance so as to prevent the diffusion of pollutants such as water and oxygen and deleterious species. Preferred high-density materials include, for example, silicon oxide containing silicon monoxide (SiO) and silicon dioxide (SiO ₂ ), silicon nitride (usually Si ₃ N ₄ ), silicon oxynitride, and aluminum oxide (usually Al ₂ O ₃ ), titanium oxide, indium tin oxide (ITO), zinc indium tin oxide, and metals such as silver, chromium, aluminum, gold and the like. The high-density material layers 122a to 122c can be formed by a method well known in the art such as resistance heating vapor deposition, sputtering, plasma-enhanced chemical vapor deposition (PECVD), electron beam method, and the like. .

  Further information regarding the formation of a multilayer barrier section can be found, for example, in U.S. Pat. Nos. 4,842,893, 4,954,371, 5,260,095, 6,224,948. The entire disclosure of these documents is hereby incorporated by reference.

  By selecting planarizing material layers 121a-121c and high-density material layers 122a-122c having appropriate transparency and sufficiently different refractive indices, the multilayer mirror 120 can be formed. Preferably, the thickness of each layer in the multilayer mirror is λ / 4 where λ is the peak wavelength of light selected to be transmitted. In the multilayer mirror structure including the multilayer mirror structure according to the present invention, the wavelength of light having a wavelength distributed within a predetermined range is normally transmitted instead of a single wavelength. Here, as is well known in the art, if the layer thickness is approximately λ / 4, the peak transmission level occurs at approximately λ. (As a result of such a transmission wavelength distribution, if the specific wavelength is reflected instead of transmitting the specific wavelength, the thickness of the layer needs to be greatly different from λ / 4.) . Such multilayer mirrors are well known and are referred to as “quater-wave stacks” based on the thickness of the layers in the multilayer mirror. It is known that the transmittance / reflectance of a multilayer mirror depends on the number of layer pairs, the layer thickness, and the refractive index of the material used.

  A preferred planarizing material and high density material pair for implementing the present invention is, for example, a polyacrylate and aluminum oxide pair.

  3 and 4 are also provided with quarter-wave stacks 220, 320a, and 320b similar to the quarter-wave stack 120 shown in FIG. These stacks include planarization material layers 221a-221c, 321a-321c and high density material layers 222a-222c, 322a-322c. The quarter wavelength stack 320b is formed on the substrate 310. On the other hand, the quarter wave stacks 220 and 320a are formed on the OLEDs 240 and 340, and these OLEDs 240 and 340 are cooperative barrier layers 221a to 221c, 222a to 222c, and 321a to 321c to be formed later. 322a to 322c function as a “substrate”.

  Although the present invention has been described using several specific embodiments, it will be apparent to those skilled in the art that various modifications can be made to the embodiments described above. These variations are within the scope of the present invention, which is limited only by the scope of the claims.

It is sectional drawing which simplifies and shows a known OLED structure. It is sectional drawing which simplifies and shows a known OLED structure. It is sectional drawing of the OLED structure which is an Example of this invention. It is sectional drawing of the OLED structure which is another Example of this invention. FIG. 5 is a cross-sectional view of an OLED structure that is yet another embodiment of the present invention.

Claims (19)

A substrate,
A first electrode formed on the substrate; a light-emitting layer formed on the first electrode; and a second electrode formed on the light-emitting layer. An organic light emitting device emitting light in a range of wavelengths;
(A) a planarization layer having a first refractive index and (b) a high-density layer having a second refractive index different from the first refractive index are alternately and continuously formed on the substrate. And a multi-layer mirror disposed in
The thicknesses of the planarization layer and the high density layer are selected such that the multilayer mirror transmits light having a peak wavelength within the predetermined range of wavelengths, and the planarization layer and the high density layer cooperate. An organic light emitting device structure characterized by preventing permeation of water and oxygen.   2. The organic light emitting device structure according to claim 1, wherein the multilayer mirror comprises a quarter wavelength stack.   3. The organic light emitting device structure according to claim 2, wherein the planarizing layer is formed of a material selected from a fluorinated polymer, parylene, cycloten, and polyacrylate.   The high-density layer is formed of a material selected from silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, titanium oxide, indium-tin oxide, zinc indium-tin oxide, and metal. 3. The organic light emitting device structure according to 2.   3. The organic light emitting device structure according to claim 2, wherein the planarizing layer is made of polyacrylate, and the high density layer is made of aluminum oxide.   The organic light-emitting device structure according to claim 2, wherein the first electrode is an anode, and the second electrode is a cathode.   The organic light-emitting device structure according to claim 2, wherein the organic light-emitting device is a top take-out type device.   The organic light emitting device structure according to claim 2, wherein the organic light emitting device is a downward take-out type device.   The organic light emitting device structure according to claim 2, wherein the organic light emitting device is a transparent device.   The organic light-emitting device structure according to claim 2, wherein the quarter-wave stack is disposed between the organic light-emitting device and the substrate, and the first electrode is a transparent electrode.   The organic light-emitting device structure according to claim 10, wherein the first electrode is a transparent anode, and the second electrode is a cathode.   The organic light-emitting device structure according to claim 11, wherein the second electrode is a reflective cathode.   11. The organic light emitting device structure according to claim 10, wherein the second electrode is a transparent electrode, and further comprises a quarter wavelength stack formed on the second electrode.   The organic light-emitting device structure according to claim 13, wherein the first electrode is a transparent anode, and the second electrode is a transparent cathode.   The organic light-emitting device structure according to claim 2, wherein the quarter-wave stack is disposed on the organic light-emitting device, and the second electrode is a transparent electrode.   16. The organic light emitting device structure according to claim 15, wherein the first electrode is an anode, and the second electrode is a transparent cathode.   The organic light-emitting device structure according to claim 16, wherein the first electrode is a reflective anode. A transparent substrate;
A transparent anode formed on the transparent substrate, having a light emitting layer formed on the transparent anode, and a reflective cathode formed on the light emitting layer. An organic light emitting device that emits light,
(A) a planarization layer having a first refractive index and (b) a high-density layer having a second refractive index different from the first refractive index are alternately and continuously formed on the substrate. A quarter-wave stack disposed in
The thicknesses of the planarization layer and the high-density layer are selected so that the quarter-wave stack transmits light having a peak wavelength within the predetermined range of wavelengths. An organic light-emitting device structure that cooperates to prevent permeation of water and oxygen. A substrate,
A reflective anode formed on the substrate, a light emitting layer formed on the reflective anode, and a transparent cathode formed on the light emitting layer, and is turned on to emit light in a predetermined range of wavelengths. An organic light emitting device that emits,
(A) a planarization layer having a first refractive index and (b) a high-density layer having a second refractive index different from the first refractive index are alternately and continuously formed on the substrate. A quarter-wave stack disposed in
The thicknesses of the planarization layer and the high-density layer are selected so that the quarter-wave stack transmits light having a peak wavelength within the predetermined range of wavelengths. An organic light-emitting device structure that cooperates to prevent permeation of water and oxygen.

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